New Piwik 2.0 breaks Joomla 1.5 backend editors

After updating to piwik 2.0 the in the administrator area I cant edit articles.
It seams that the .xml files from editor cant be loaded.
I have lots of XML loading errors like this if I open a article.

ERROR_XML_LOAD
/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/jce.xml
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/jce.xml"
ERROR_XML_LOAD
/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/models/plugins.xml
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/jce.xml"
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/models/plugins.xml"
ERROR_XML_LOAD
/var/www/virtual/XXXXXXXXXXX/components/com_jce/editor/tiny_mce/plugins/anchor/anchor.xml
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/jce.xml"
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/administrator/components/com_jce/models/plugins.xml"
XML: failed to load external entity "/var/www/virtual/XXXXXXXXXXX/components/com_jce/editor/tiny_mce/plugins/anchor/anchor.xml"

and much more of that...

Any ideas to solve this problem?